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US 6,345,502 B1Granted
Micromachined parylene membrane valve and pump
AssigneeCalifornia Institute of Technology
InventorsYu-Chong Tai, Xing Yang, Charles Grosjean, Xuan-Qi Wang
Life of this patent
Estimating the term…
Abstract
A micromachined fluid handling device having improved properties. The valve is made of reinforced parylene. A heater heats a fluid to expand the fluid. The heater is formed on unsupported silicon nitride to reduce the power. The device can be used to form a valve or a pump. Another embodiment forms a composite silicone/parylene membrane. Another feature uses a valve seat that has concentric grooves for better sealing operation.
Claims29
A thermopneumatic actuator comprising:
- a base;
- a cavity formed from sidewalls of micromachined silicon;
- a membrane, formed from a silicon substrate, formed to have first and second sidewalls and an open space between said first and second sidewalls, a first layer of membrane material extending over said open space;
- and a second layer of membrane material, extending along said sidewalls, under said first layer of membrane material to thereby form strengthened edge portions at locations where said sidewalls meet said first layer of membrane material;
- and
- a free standing heater, located in said cavity and formed from a thinned material which has low thermal conductivity , and operating to selectively heat thermopneumatic liquid in said cavity to expand the membrane or cool the thermopneumatic liquid to contract the membrane.
3 more elements
A peristaltic pump, comprising:
- a housing;
- a plurality of heaters, located in series with one another and inside said housing spaced from one another at a predetermined spacing;
- each said heater comprising a supporting sidewall formed of a silicon material;
- a thin material of a thickness less than 2 μm thick, having a low thermal conductivity, extending between said sidewalls, and having an unsupported portion which is unsupported by any material with a higher thermal conductivity;
- and a resistive heater portion, formed on said unsupported portion of said low thermal conductivity material;
- a plurality of expandable membranes, located spaced a similar spacing to a spacing between said heaters and located adjacent said heaters;
- and
- an inlet outlet portion, having an inlet near a first of said membranes, an outlet near a last of said membranes, wherein said heaters are selectively actuated in turn to expand said membranes and to pump fluid from said first membrane via the other membranes finally to last membrane and out said outlet.
5 more elements
A thermopneumatic device, comprising
- a micro machined cavity, having walls formed of silicon and holding an thermopneumatically expandable liquid;
- a heater, located within said cavity, and selectively actuated to selectively expand said liquid and de-actuated to contract said liquid;
- and
- a membrane, in contact with liquid in the cavity, having a liquid impermeable film layer which has low permeability to the thermopneumatic actuation fluid, and an elastomeric substance, forming a sealing surface, said elastomeric material being isolated from the thermopneumatic actuation fluid by said liquid impermeable layer.
1 more element
Dependencies are inferred from the claim text.